WO2018230514A1 - Hydrophilic-coating-film forming composition and hydrophilic coating film using same - Google Patents

Abstract

Provided are a hydrophilic coating film of which hydrophilicity and anti-fogging properties do not deteriorate even during storage under high-temperature and high-humidity conditions and a hydrophilic-coating-film forming composition with which said film is obtained. The present invention provides a hydrophilic-coating-film forming composition containing a siloxane monomer having a betaine group having a positive charge on a nitrogen atom in a nitrogen-containing heterocyclic structure, such as a compound represented by formula [1], and water or an organic solvent. [1] (In the formula, R1 represents an alkyl group having a carbon number of 1 to 5; R2 represents an alkyl group, etc. having a carbon number of 1 to 5; p represents 1 to 3; q represents 0 to 2 when p is 1, 0 to 1 when p is 2, and 0 when p is 3; L represents a straight-chain or branched-chain alkylene group that has a carbon number of 1 to 20 and that may have a hetero atom; X represents a single bond, etc.; Y represents a divalent organic group having a nitrogen-containing hetero ring; M represents a straight-chain or branched-chain alkylene group having a carbon number of 1 to 10 and bonded to a nitrogen atom in Y, wherein either one of M and L forms an N+ moiety through bonding to the nitrogen atom in Y; and Z represents COO-, SO3 -, etc.)

Description

Composition for forming hydrophilic coat film and hydrophilic coat film using the same

The present invention relates to a composition for forming a hydrophilic coat film having a hydrophilic surface and an antifogging effect, and a hydrophilic coat film using the same.

As surface characteristics required for a substrate, antifogging properties, antistatic properties, antifouling properties, biocompatibility and the like are known. These surface characteristics are generally achieved by imparting hydrophilicity by coating (coating) a hydrophilic film on the surface of the substrate.
Examples of the polymer that can impart hydrophilicity to the substrate include a phosphoryl group-containing methacrylate polymer (see Patent Document 1) and a compound having a betaine group that has a very strong interaction with water and a covalent bond with an inorganic base material. A compound in which a functional group capable of forming a compound is introduced (see Patent Document 2) is known.

However, these materials have a problem that the surface characteristics such as hydrophilicity and antifogging properties are gradually or rapidly deteriorated by storage under high temperature and high humidity conditions.

Japanese Unexamined Patent Publication No. 6-313209

The present invention has been made in view of these points, and an object of the present invention is to form a hydrophilic coating film in which surface properties such as hydrophilicity and antifogging properties do not deteriorate even when stored under high temperature and high humidity conditions. It is providing the composition for water and the hydrophilic coating film which can obtain it.

Thus, the present invention has the following gist.
[1] A hydrophilic coating film-forming composition comprising a siloxane monomer having a betaine group having a positive (+) charge on a nitrogen atom in a nitrogen-containing heterocyclic structure, and water or an organic solvent.
[2] A method for forming a hydrophilic coat, wherein the composition for forming a hydrophilic coat film described above is coated on a substrate to form a coating film, the coating film is dried and baked to obtain a coating film.
[3] A hydrophilic coat film obtained from the composition for forming a hydrophilic coat film described above.

According to the present invention, it is possible to provide a hydrophilic coating film-forming composition that does not deteriorate hydrophilicity and antifogging property even when stored under high temperature and high humidity conditions, and a hydrophilic coating film from which it can be obtained.
The hydrophilic coating film obtained from the composition for forming a hydrophilic coating film of the present invention can be used for water droplet adhesion prevention films, antifogging films, etc. for lenses such as glasses and cameras, windows of buildings, cars, etc. it can.

The composition for forming a hydrophilic coat film of the present invention includes a siloxane monomer having a betaine group having a positive (+) charge on a nitrogen atom in a nitrogen-containing heterocyclic structure (hereinafter also referred to as a specific siloxane monomer), and water. Or it contains an organic solvent.

<Specific siloxane monomer>
The composition for forming a hydrophilic coat film of the present invention has a siloxane monomer having a betaine group having a positive charge on a nitrogen atom in a nitrogen-containing heterocyclic structure.
Betaine is a compound that has positive and negative charges at non-adjacent positions in the same molecule, and has no positively charged hydrogen atoms bound to dissociable hydrogen atoms, and the molecule as a whole has no charge. is there.

The positive charge of the betaine group contained in the specific siloxane monomer is present on the nitrogen atom on the nitrogen-containing heterocycle. Examples of nitrogen-containing heterocycles include pyridine, piperidine, imidazole, oxazole, thiazole, pyrazole, imidazoline, pyrazine, benzimidazole, quinoline, isoquinoline, purine, quinoxaline, and the like, among which pyridine or imidazoline is preferable.

The specific siloxane monomer is represented by the following general formula.

In the above formula [1], R ₁ represents an alkyl group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms.
R ₂ represents an alkyl group having 1 to 5 carbon atoms, preferably 1 to 4 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, preferably 2 to 4 carbon atoms, or an alkynyl group having 2 to 5 carbon atoms, preferably 2 to 4 carbon atoms. To express. Any hydrogen atom of R ₂ may be substituted with an alkyl group having 1 to 5 carbon atoms, a halogen atom such as a fluorine atom, an aromatic ring, or an aliphatic ring. p represents an integer of 1 to 3. q represents an integer of 0 to 2 when p is 1, represents an integer of 0 to 1 when p is 2, and represents 0 when p is 3.

L represents a linear or branched alkylene group which may have a hetero atom having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms. Any hydrogen atom of the alkylene group may be substituted with an alkyl group having 1 to 5 carbon atoms, preferably 1 to 4 carbon atoms, or a halogen atom such as a fluorine atom, an aromatic ring, or an aliphatic ring. Among these, a linear or branched alkylene group having 2 to 7, preferably 2 to 6 carbon atoms is preferable. Here, the hetero atom means oxygen, nitrogen, sulfur, or phosphorus, and oxygen, nitrogen, or sulfur is preferable.

X represents a single bond, —O—, —COO—, —OCO—, —CONR ₃ —, —NR ₄ —CO—, or —NR ₅ ═NR ₆ —. R ₃ , R ₄ , R ₅ and R ₆ each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, preferably 1 to 3 carbon atoms.
Y represents a divalent organic group containing a nitrogen-containing heterocyclic ring. Examples include pyridine, piperidine, imidazole, oxazole, thiazole, pyrazole, imidazoline, pyrazine, benzimidazole, quinoline, isoquinoline, purine, quinoxaline, etc. Among them, pyridine or imidazoline is preferable.

M represents a linear or branched alkylene group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, and any hydrogen atom of the alkylene group is an alkyl group having 1 to 5 carbon atoms, preferably 1 to 4 carbon atoms. Alternatively, it may be substituted with a halogen atom such as a fluorine atom. Among these, a linear or branched alkylene group having 2 to 7, preferably 2 to 6 carbon atoms is preferable. M is bonded to the nitrogen atom of Y, and one of M and L forms an N ⁺ moiety by the bond with the nitrogen atom of Y.
Z represents COO ⁻ , SO ₃ ⁻ , or PO ₄ ^— . From the viewpoint of durability of the resulting coating film, SO ₃ ^- is preferable.

Although the specific example of a specific siloxane monomer is illustrated below, it is not limited to these.

In the formula, Me represents a methyl group, and Et represents an ethyl group. For the N ⁺ moiety, tautomers are also included.
Especially, as a specific siloxane monomer, the following are preferable from a viewpoint of monomer stability and raw material availability.

<Method for producing specific siloxane monomer>
The specific siloxane monomer used in the present invention is, for example, in the case of a sulfonic acid terminal, a nitrogen-containing heterocyclic structure-containing silicon compound, a sultone ring such as 1,3-propane sultone, 1,4-butane sultone, or 2,4-butane sultone. It can be produced by reacting a compound.

In the case of a carboxylic acid terminal, it can be obtained by reacting a nitrogen-containing heterocyclic structure-containing silicon compound with a lactone ring compound such as β-propiolactone. Moreover, a carboxylic acid terminal compound can also be obtained by a method of adding acrylic acid to a nitrogen-containing heterocyclic structure-containing silicon compound. Carboxylic acid terminal compounds can also be obtained by reacting alkali metal haloacetates such as potassium monochloroacetate, sodium monochloroacetate, potassium monobromoacetate and sodium monobromoacetate with silicon compounds containing nitrogenous heterocyclic structures in non-aqueous solvents. I can do it.

Reaction solvents include water, alcohols (methanol, ethanol, 2-propanol, etc.), aprotic polar organic solvents (dimethylformamide, dimethyl sulfoxide, dimethylacetamide, N-methylpyrrolidone, etc.), ethers (diethyl ether, diisopropyl, etc.) Ether, tert-butyl methyl ether, cyclopentyl methyl ether, tetrahydrofuran, dioxane, etc.), aliphatic hydrocarbons (pentane, hexane, heptane, petroleum ether, etc.), aromatic hydrocarbons (benzene, toluene, xylene, mesitylene, Chlorobenzene, dichlorobenzene, nitrobenzene, tetralin, etc.), halogenated hydrocarbons (chloroform, dichloromethane, carbon tetrachloride, dichloroethane, etc.), lower fatty acid esters (acetic acid) Chill, ethyl acetate, butyl acetate, methyl propionate, etc.), nitriles (acetonitrile, propionitrile, butyronitrile, etc.), etc. can be used. These solvents can be appropriately selected in consideration of the ease of reaction and the like, and can be used alone or in combination of two or more. Moreover, depending on the case, the said solvent can also be used as a solvent which does not contain water using a suitable dehydrating agent and a desiccant.
Preferred solvents include acetonitrile or tetrahydrofuran.

The reaction time is 30 minutes to 180 hours, preferably 2 to 120 hours, and particularly preferably 5 to 100 hours.
As the nitrogen-containing heterocyclic structure-containing silicon compound as a raw material, a commercially available one can be used, or it can be easily obtained by a known method. The reaction temperature is preferably 0 ° C. to the boiling point of each solvent, more preferably 0 ° C. to 120 ° C., particularly preferably 5 ° C. to 100 ° C.

When the specific siloxane monomer, which is a reaction product, is precipitated in the reaction organic solvent, it can be purified by a method such as filtration and drying. When the reaction proceeds from beginning to end in a homogeneous system, the reaction product obtained may be used as it is, but when the specific siloxane monomer as a target is a solid, crystallization by adding a poor solvent after concentrating the reaction solvent or It can be isolated and purified by a known method such as reprecipitation.

<Other ingredients>
The composition for forming a hydrophilic coating film of the present invention is selected from the group consisting of a specific siloxane monomer, water or an organic solvent, a metal alkoxide, a metal alkoxydrigomer, a metal alkoxide polymer, inorganic fine particles, a leveling agent and a surfactant. You may contain at least 1 or more types.

The metal alkoxide is included in order to increase the mechanical stability of the formed coating film. Examples of the metal alkoxide include silicon, titanium, aluminum, tantalum, antimony, bismuth, tin, indium, and zinc. Can be mentioned. Among these, silicon, titanium, or zirconium is preferable from the viewpoint of availability.

Examples of the metal alkoxide include those represented by the following formula (II) or (III).
M ¹ (OR ² ) n (II)
In the formula (II), R ² represents an alkyl group or an acetyl group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms. n represents an integer of 2 to 5. M ¹ is preferably silicon (Si), titanium (Ti), zirconium (Zr), or aluminum (Al), and particularly preferably silicon (Si) or titanium (Ti). N is preferably 3 or 4.

R ³ _x M ¹ (OR ² ) _4-x (III)
In formula (III), M ¹ and R ² are as defined in formula (I) above. R ³ may be substituted with a hydrogen atom, a halogen atom, a vinyl group, a styryl group, a phenyl group, a naphthyl group, an acryl group, a methacryl group, or an aryl group, and may contain a hetero atom. It is a group selected from the group consisting of alkyl groups having 1 to 30 carbon atoms. x is an integer of 1 to 3. Here, the hetero atom is oxygen, nitrogen, sulfur or phosphorus, preferably oxygen, nitrogen or sulfur.

Examples of the metal alkoxide represented by the above formula (II) include silicon alkoxide such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetraacetoxysilane, titanium tetraethoxide, titanium tetrapropoxide, Titanium alkoxide such as titanium tetrabutoxide, zirconium tetraethoxide, zirconium tetrapropoxide, zirconium tetraalkoxide such as zirconium tetrabutoxide, aluminum trialkoxide compounds such as aluminum tributoxide, aluminum triisopropoxide, aluminum triethoxide, tantalum Tantalum pentaalkoxide such as pentapropoxide and tantalum pentaboxide And the like. These can be used alone or in combination of two or more.

When M ^{1 in the} above formula (III) is silicon and R ³ is a hydrogen atom, examples thereof include trimethoxysilane, triethoxysilane, tripropoxysilane, and tributoxysilane. These can be used alone or in combination of two or more.

When M ^{1 in the} above formula (III) is silicon and R ³ is an organic group, for example, methyltrimethoxysilane, methyltripropoxysilane, methyltriacetoxysilane, methyltributoxysilane, methyltripentoxysilane , Methyltriamyloxysilane, methyltriphenoxysilane, methyltribenzyloxysilane, methyltriphenethyloxysilane, glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, α-glycidoxyethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, α-glycidoxypropyltrimethoxysilane, α-glycidoxypropyltriethoxysilane, β-Gly Sidoxypropyltrimethoxysilane, β-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltripropoxysilane, γ-glycyl Sidoxypropyltributoxysilane, γ-glycidoxypropyltriphenoxysilane, α-glycidoxybutyltrimethoxysilane, α-glycidoxybutyltriethoxysilane, β-glycidoxybutyltriethoxysilane, γ-glycyl Sidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane, δ-glycidoxybutyltrimethoxysilane, δ-glycidoxybutyltriethoxysilane, (3,4-epoxycyclohexyl) methyltrimethoxysilane, (3,4-epoki (Cyclohexyl) methyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltripropoxy Silane, β- (3,4-epoxycyclohexyl) ethyltributoxysilane, β- (3,4-epoxycyclohexyl) ethyltriphenoxysilane, γ- (3,4-epoxycyclohexyl) propyltrimethoxysilane, γ- ( 3,4-epoxycyclohexyl) propyltriethoxysilane, δ- (3,4-epoxycyclohexyl) butyltrimethoxysilane, δ- (3,4-epoxycyclohexyl) butyltriethoxysilane, glycidoxymethylmethyldimethoxysilane, Guri Sidoxymethylmethyldiethoxysilane, α-glycidoxyethylmethyldimethoxysilane, α-glycidoxyethylmethyldiethoxysilane, β-glycidoxyethylmethyldimethoxysilane, β-glycidoxyethylethyldimethoxysilane, α -Glycidoxypropylmethyldimethoxysilane, α-glycidoxypropylmethyldiethoxysilane, β-glycidoxypropylmethyldimethoxysilane, β-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ-glycidoxyp Propylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane, γ-glycidoxypropylvinyldimethoxysilane, γ-glycidoxypropylvinyldiethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, γ- Chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropyltriacetoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane , Β-cyanoethyltriethoxysilane, chloromethyltrimethoxysilane, chloromethyltriethoxysilane, N- (β-aminoethyl) γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) γ-aminopropyl Pyrmethyldimethoxysilane, γ-aminopropylmethyldimethoxysilane, N- (β-aminoethyl) γ-aminopropyltriethoxysilane, N- (β-aminoethyl) γ-aminopropylmethyldiethoxysilane, dimethyldimethoxysilane, Phenylmethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldiethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptomethyl Diethoxysilane, γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, γ-ureidopropyltripropoxysilane, (R) -N-1-phenylethyl-N′-tri Toxisilylpropylurea, (R) -N-1-phenylethyl-N'-trimethoxysilylpropylurea, 3-isocyanatopropyltriethoxysilane, trifluoropropyltrimethoxysilane, bromopropyltriethoxysilane, diethyldiethoxysilane , Diethyldimethoxysilane, trimethylethoxysilane, trimethylmethoxysilane and the like. These can be used alone or in combination of two or more.

The above metal alkoxide oligomer and metal alkoxide polymer are contained in order to increase the mechanical stability of the formed coating film. As these metals, single or composite oxide precursors such as silicon, titanium, aluminum, tantalum, antimony, bismuth, tin, indium, and zinc are used. As a metal alkoxide oligomer and a metal alkoxide polymer, even if it is a commercial item, what was obtained by conventional methods, such as a hydrolysis, from monomers, such as metal alkoxide, may be sufficient.

Specific examples of commercially available metal alkoxydrigomers and metal alkoxide polymers include siloxane oligomers or siloxane polymers such as methyl silicate 51, methyl silicate 53A, ethyl silicate 40, ethyl silicate 48, EMS-485, and SS-101 manufactured by Colcoat. Examples thereof include titanoxane oligomers such as titanium-n-butoxide tetramer manufactured by Kanto Chemical. These may be used alone or in combination.

Further, the leveling agent, the surfactant and the like are contained in order to improve the uniformity of the coating film, and known ones can be used, and commercially available products are particularly preferable because they are easily available.
As the inorganic fine particles, silica fine particles, alumina fine particles, titania fine particles, magnesium fluoride fine particles and the like are preferable, and a colloidal solution of these inorganic fine particles is particularly preferable. The colloidal solution may be a dispersion of inorganic fine particle powder in a dispersion medium or a commercially available colloidal solution.

By incorporating inorganic fine particles into the composition of the present invention, it is possible to impart the surface shape of the formed cured film and other functions. The inorganic fine particles preferably have an average particle size of 0.001 to 0.2 μm, more preferably 0.001 to 0.1 μm. When the average particle diameter exceeds 0.2 μm, the transparency of the cured film formed using the prepared coating liquid may be lowered. The average particle size is 50% volume average particle size (D50).

Examples of the dispersion medium of the inorganic fine particles include water or an organic solvent. As the colloidal solution, the pH or pKa is preferably adjusted to 1 to 10, more preferably 2 to 7, from the viewpoint of the stability of the coating solution for film formation.
Organic solvents used for the dispersion medium of inorganic fine particles include methanol, ethanol, propanol, butanol, ethylene glycol, propylene glycol, butanediol, pentanediol, 2-methyl-2,4-pentanediol, diethylene glycol, dipropylene glycol, ethylene Alcohols such as glycol monopropyl ether; ketones such as methyl ethyl ketone and methyl isobutyl ketone; aromatic hydrocarbons such as toluene and xylene; amides such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone; ethyl acetate and butyl acetate And esters such as γ-butyrolactone; ethers such as tetrahydrofuran and 1,4-dioxane. Of these, alcohols or ketones are preferable. These organic solvents can be used alone or in admixture of two or more as a dispersion medium.

Among the other components that may be contained, preferred are metal alkoxides, metal oxide sols, or metal alkoxy digomers in which a part of the alkoxy groups may be substituted with other organic groups.
The content of the metal alkoxide, metal oxide sol or metal alkoxy driomer in the composition of the present invention is 0.5 to 100 parts by mass, preferably 1 to 60 parts by mass with respect to 100 parts by mass of the specific siloxane monomer. Part. Within such a range, the hydrophilicity and film stability of the composition of the present invention can be more exhibited.

<Hydrophilic coating film forming composition>
The composition for forming a hydrophilic coat film of the present invention is a solution obtained by mixing a specific siloxane monomer and one or more of water or an organic solvent.
Organic solvents include alcohols such as methanol, ethanol, 2-propanol, butanol, diacetone alcohol, trifluoroethanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, ethylene glycol, diethylene glycol, propylene glycol, hexylene Glycols such as glycol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, propylene Glycol monomethyl ether Glycol ethers such as propylene glycol monobutyl ether, esters such as acetic acid methyl ester, acetic acid ethyl ester, and lactate ethyl ester, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, γ- Examples include butyrolactone, dimethyl sulfoxide, tetramethylurea, hexamethylphosphotriamide, and m-cresol.
Among them, organic solvents include alcohols such as methanol, ethanol, 2-propanol, and trifluoroethanol, glycols such as ethylene glycol, propylene glycol, and hexylene glycol, methyl cellosolve, and ethyl, from the viewpoint of monomer solubility. Cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, etc. Glycol ether or N-methyl-2 Preferably a pyrrolidone.

The specific siloxane monomer contained in the solution may be hydrolyzed. For hydrolysis of specific siloxane monomers, acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, formic acid, succinic acid, maleic acid; alkalis such as ammonia, methylamine, ethylamine, ethanolamine, triethylamine or metal salts such as hydrochloric acid, sulfuric acid, nitric acid A catalyst such as may be used.
In carrying out the hydrolysis, the reaction temperature is preferably 0 ° C. to boiling point, more preferably 0 ° C. to 120 ° C., particularly preferably 5 ° C. to 80 ° C. The reaction time is preferably 10 minutes to 80 hours, more preferably 30 minutes to 50 hours, and particularly preferably 30 minutes to 2 hours.

In the present invention, the solution obtained by the above-described method may be used as a coating forming composition as it is, or the solution obtained by the above-described method may be concentrated or diluted by adding a solvent, if necessary. Or may be replaced with another solvent.
In this case, the solvent used may be the same solvent used for dissolution or another solvent. This solvent is not particularly limited as long as the silicon compound is uniformly dissolved, and one kind or plural kinds of solvents can be arbitrarily selected and used.
The content of the specific siloxane monomer in the composition of the present invention is preferably 0.005 to 15% by mass, more preferably 0.01 to 12% by mass in terms of SiO ₂ solid content concentration. Within such a concentration range, it is easy to obtain a desired film thickness by a single application, and a sufficient pot life of the solution is easily obtained.

<Film formation>
The hydrophilic coating film-forming composition of the present invention can be formed into a hydrophilic coating film by applying a known coating method to form a coating film on a substrate. Examples of coating methods include dip coating, spin coating, spray coating, flow coating, brush coating, bar coating, gravure coating, roll transfer, blade coating, air knife coating, and slit coating. Method, screen printing method, ink jet method, flexographic printing method and the like are used. Among these, a spin coating method, a slit coating method, a blade coating method, a spray coating method, or a dip coating method is preferable.

<Board>
As a substrate, glass, plastic {polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, ABS, polycarbonate, polystyrene, epoxy, unsaturated polyester, melamine, diallyl phthalate, polyimide, urethane, nylon, polyethylene, polypropylene, Cycloolefin polymer, polyvinyl chloride, fluorine resin (polytetrafluoroethylene resin, polychlorotrifluoroethylene resin, polyvinylidene fluoride resin, polyvinyl fluoride resin, perfluoroalkoxy fluorine resin, ethylene tetrafluoride / hexafluoropropylene copolymer) Combined resin, ethylene / tetrafluoroethylene copolymer resin, ethylene / chlorotrifluoroethylene copolymer resin, etc.), polybutadiene , Polyisoprene, SBR, nitrile rubber, EPM, EPDM, epichlorohydrin rubber, neoprene rubber, porsulfide, butyl rubber, etc.}, metal (iron, aluminum, stainless steel, titanium, copper, brass, alloys thereof, etc.), cellulose, cellulose Examples include derivatives, cellulose analogs (chitin, chitosan, porphyran, etc.) or natural fibers (silk, cotton, etc.) and the like, sheets, films, fiber surface hydrophilization, and the like.

In addition, in order to improve the adhesion to the substrate or the like as necessary, the substrate is previously subjected to primer treatment, vacuum plasma, atmospheric pressure plasma, corona discharge treatment, flame treatment, intro treatment, ultraviolet irradiation, ozone treatment, etc. Surface activation treatment (a technique for increasing the surface energy of the substrate surface) may be performed.

<Drying>
The hydrophilic coating film of the present invention is obtained by drying and baking the coating film of the composition for forming a hydrophilic coating film formed on the substrate. The drying step is preferably in the temperature range of room temperature to 150 ° C, and more preferably in the range of 40 to 120 ° C. The time is preferably about 30 seconds to 10 minutes, more preferably about 1 to 8 minutes. As a drying method, it is preferable to use a hot plate, a hot air circulating oven, or the like.

<Baking>
The firing step is preferably in the temperature range of 80 ° C. to 300 ° C. and more preferably in the range of 100 ° C. to 250 ° C. in consideration of the heat resistance of the substrate and the environmental aspects. The time is preferably 5 minutes or more, and more preferably 15 minutes or more. As a baking method, it is preferable to use a hot plate, a thermal circulation oven, an infrared oven, or the like.

The thickness of the film obtained by the above method can be selected as necessary. The thickness of the coating is preferably 3 to 150 nm because the stability of the hydrophilic coating film can be easily obtained. More preferably, it is 5 to 120 nm.

EXAMPLES Hereinafter, although this invention is demonstrated in more detail according to an Example, this invention is not limited to these.
Abbreviations below are as follows.
DHIMES: triethoxy-3- (2-imidazolin-1-yl) propylsilane p-PyTES: 2- (4-pyridylethyl) triethoxysilane DMAPS: 3- (N, N-dimethylaminopropyl) trimethoxysilane MTES: Methyltriethoxysilane TFE: trifluoroethanol

The products in the following synthesis examples were identified by 1H-NMR analysis. The analysis conditions are as follows.
Apparatus: Varian NMR System 400 NB (400 MHz)
Measuring solvent: CDCl3, DMSO-d6,
Reference substance: Tetramethylsilane (TMS) (δ0.0 ppm for 1H)

<Synthesis Example 1: Synthesis of A-1>

A reactor was charged with acetonitrile (398.9 g) and DHIMES (199.5 g, 727 mmol), and then 1,3-propane sultone dissolved in acetonitrile (299.3 g) under a nitrogen atmosphere and ice-cooling conditions. (97.7 g) was added dropwise using a dropping funnel.
After the dropping, the residue remaining on the dropping funnel was poured with acetonitrile (99.8 g), and the reaction was carried out at room temperature for 18 hours. After completion of the reaction, the total internal weight in the reaction vessel was reduced to 459 g by concentration under reduced pressure, tetrahydrofuran (1596 g) was added to precipitate crystals, filtered and dried to give A-1 (property: white crystals) to 244. 0 g was obtained (yield: 85%).
¹ H-NMR (400 MHz) in CDCl ₃ : 0.57 to 0.61 ppm (m, 2H), 1.23 ppm (t, J = 7.2 Hz, 9H), 1.69 to 1.76 ppm (m, 2H) ), 2.14-2.21 ppm (m, 2H) 2.90 ppm (t, J = 7.2 Hz, 2H), 3.57 ppm (t, J = 7.2 Hz, 2H), 3.78-3. 85 ppm (m, 8H), 3.93-3.99 ppm (m, 4H), 8.82 ppm (s, 1H)

<Synthesis Example 2: Synthesis of A-2>
The procedure was the same as in Synthesis Example 1, except that p-PyTES was used as the siloxane monomer, to obtain 40.5 g of A-2 (property: red crystals) (yield 74%).

<Synthesis Example 3: Synthesis of A-3>
The same procedure as in Synthesis Example 1 was carried out except that DMAPS was used as the siloxane monomer to obtain 49.4 g of A-3 (property: white crystals) (yield 82%).

<Synthesis Example 4: Synthesis of A-4>
DHIMES (20.0 g, 72.9 mmol) was charged in acetonitrile (30.1 g), and 1,4-butane sultone (11.0 g) was added under a nitrogen atmosphere at room temperature. Subsequently, the reaction temperature was set to 45 ° C. and the reaction was carried out for about 2 days to disappear the raw materials. After completion of the reaction, the solvent was removed by concentration under reduced pressure, and ethyl acetate (20.0 g) and hexane (20.0 g) were added to prepare a suspension solution. Crystals were recovered by allowing the suspension to stand overnight in a freezer at −25 ° C., and the crystals were recovered by filtration under a nitrogen atmosphere. The obtained crystals were slurry washed with hexane (50.0 g), filtered and dried to obtain 20.2 g of A-4 (property: light yellow crystals) (yield: 67%).

<Synthesis Example 5: Synthesis of A-5>
Triethoxy-3- (2-imidazolin-1-yl) propylsilane (20.0 g, 72.9 mmol) was charged in acetonitrile (40.0 g), and 2,4-butanesultone (10. 4 g) was added. Subsequently, the reaction temperature was set to room temperature and the reaction was carried out for about 1 day to disappear the raw materials. After completion of the reaction, the solvent was removed by concentration under reduced pressure. Subsequently, the concentrated solution was diluted with ethyl acetate (80.0 g), and hexane (80.0 g) was added to prepare a suspension solution. The viscous substance was solidified in a freezer at −25 ° C., and the supernatant was removed. Ethyl acetate (70.0 g) and hexane (70.0 g) were added again to prepare a suspension, which was then left again in a freezer at −25 ° C. As a result, crystals were deposited. Filtration under a nitrogen atmosphere, washing with hexane, and drying gave 28.2 g of A-5 (property: white crystals) (yield: 94%).

<Preparation Example 1>
39.7 g of A-1 and 36.4 g of TFE were added to a 200 mL flask and stirred to dissolve A-1. Thereto was added a mixture of 0.3 g of succinic acid, 5.4 g of water, and 18.2 g of TFE, and the mixture was stirred at room temperature for 2 hours to obtain a solution AA.
In a 500 mL flask, 2.5 g of solution AA and 297.5 g of TFE were mixed, and further stirred at room temperature for 30 minutes to obtain a solution (K1).

<Preparation Example 2>
In a 200 mL flask, 39.1 g of A-2 and 36.7 g of TFE were added and stirred to dissolve A-2. Thereto was added a mixture of 0.3 g of succinic acid, 5.4 g of water, and 18.4 g of TFE, and the mixture was stirred at room temperature for 2 hours to obtain a solution AB.
In a 500 mL flask, 2.5 g of solution AB and 297.5 g of TFE were mixed and further stirred at room temperature for 30 minutes to obtain a solution (K2).

<Preparation Example 3>
In a 200 mL flask, 27.8 g of A-1, 5.3 g of MTES, and 40.8 g of TFE were added and stirred to dissolve A-1 and MTES. Thereto was added a mixture of 0.3 g of succinic acid, 5.4 g of water, and 20.4 g of TFE, and the mixture was stirred at room temperature for 2 hours to obtain a solution AC.
In a 500 mL flask, 2.5 g of the solution AC and 297.5 g of TFE were mixed, and the mixture was further stirred at room temperature for 30 minutes to obtain a solution (K3).

<Preparation Example 4>
In a 200 mL flask, 32.9 g of A-3 and 40.9 g of TFE were added and stirred to dissolve A-3. Thereto was added a mixture of 0.3 g of succinic acid, 5.4 g of water, and 20.5 g of TFE, and the mixture was stirred at room temperature for 2 hours to obtain a solution AD.
In a 500 mL flask, 2.5 g of the solution AD and 297.5 g of TFE were mixed, and further stirred at room temperature for 30 minutes to obtain a solution (K4).

<Preparation Example 5>
In a 100 mL flask, 16.4 g of A-4 and 14.2 g of TFE were added and stirred to dissolve A-3. Thereto was added a mixture of 0.1 g of oxalic acid, 2.2 g of water, and 7.1 g of TFE, and the mixture was stirred at room temperature for 2 hours to obtain a solution AE.
In a 500 mL flask, 2.5 g of solution AE and 297.5 g of TFE were mixed, and the mixture was further stirred at room temperature for 30 minutes to obtain a solution (K5).

<Preparation Example 6>
In a 100 mL flask, 16.4 g of A-5 and 14.2 g of TFE were added and stirred to dissolve A-3. Thereto was added a mixture of 0.1 g of oxalic acid, 2.2 g of water, and 7.1 g of TFE, and the mixture was stirred at room temperature for 2 hours to obtain a solution AF.
In a 500 mL flask, 2.5 g of the solution AF and 297.5 g of TFE were mixed and further stirred at room temperature for 30 minutes to obtain a solution (K6).

<Film formation method>
The solutions K1 to K6 obtained in the above Preparation Examples 1 to 6 were filtered under pressure through a membrane filter having a pore size of 0.5 μm, and a film was formed on a glass substrate by a spin coating method. This substrate was dried on a hot plate at 70 ° C. for 3 minutes and then baked in a hot air circulation oven at 200 ° C. for 30 minutes to obtain a hydrophilic coating.
The hydrophilic coatings (KL1 to KL5) of the solutions K1 to K3 and K5 to K6 obtained in Preparation Examples 1 to 3, 5 to 6, respectively, were designated as Examples 1 to 5. The hydrophilic coating (KM1) of the solution K4 obtained in Preparation Example 4 was used as Comparative Example 1.

The following tests were conducted on the coatings of Examples 1 to 3, 5 to 6 (KL1 to KL5) and the coating of Comparative Example 1 (KM1), and the results are shown in Table 1.
<Water contact angle>
Using an automatic contact angle meter CA-Z type manufactured by Kyowa Interface Science Co., Ltd., the contact angle when 1 microliter of pure water was dropped was measured.
<High temperature and high humidity test>
Each of the above coatings (KL1 to KL5, KM1) was aged for 3 days in a high temperature and high humidity oven with a temperature of 60 ° C. and a relative humidity of 90%. Then, the water contact angle was measured by the said method.

<Water immersion test>
Each of the coatings (KL1 to KL5, KM1) was subjected to ultrasonic cleaning with pure water at room temperature for 5 minutes, and then dried in a hot air circulation oven at 80 ° C. for 10 minutes. Thereafter, the high temperature and high humidity test was performed.
<Breath test>
Breathing was blown on the coatings (KL1 to KL5, KM1) subjected to the water immersion test and the high-temperature and high-humidity test, and each evaluation was carried out as ◯ when the surface of the non-film was not clouded and as x when cloudy.

In the coatings of Examples 1 to 5, the hydrophilicity was maintained even after the high-temperature and high-humidity test and the water immersion test, and the results of the breath test showed that the antifogging property was also maintained. . In the film of Comparative Example 1, the hydrophilicity was lowered after 3 days at high temperature and high humidity by the water immersion test, and the non-membrane surface was clouded and the antifogging property was also lowered in the breath test.
It should be noted that the entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2017-117151 filed on June 14, 2017 are cited herein as disclosure of the specification of the present invention. Incorporate.

Claims (14)

1. A hydrophilic coating film-forming composition containing a siloxane monomer having a betaine group having a positive (+) charge on a nitrogen atom in a nitrogen-containing heterocyclic structure, and water or an organic solvent.
2. The composition for forming a hydrophilic coat film according to claim 1, wherein the siloxane monomer is represented by the following formula [1].
   

   

   In the formula [1], R ₁ represents an alkyl group having 1 to 5 carbon atoms.
   R ₂ represents an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an alkynyl group having 2 to 5 carbon atoms, and an arbitrary hydrogen atom that R ₂ has has 1 to 5 carbon atoms It may be substituted with an alkyl group, a halogen atom, an aromatic ring, or an aliphatic ring. p represents an integer of 1 to 3. q represents an integer of 0 to 2 when p is 1, represents an integer of 0 to 1 when p is 2, and represents 0 when p is 3.
   L represents a linear or branched alkylene group which may have a hetero atom having 1 to 20 carbon atoms, and an arbitrary hydrogen atom of the alkylene group is an alkyl group having 1 to 5 carbon atoms, a halogen atom, It may be substituted with an aromatic ring or an aliphatic ring.
   X represents a single bond, —O—, —COO—, —OCO—, —CONR ₃ —, —NR ₄ —CO—, or —NR ₅ ═NR ₆ —. R ₃ , R ₄ , R ₅ and R ₆ each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
   Y represents a divalent organic group having a nitrogen-containing heterocyclic ring.
   M represents a linear or branched alkylene group having 1 to 10 carbon atoms, and any hydrogen atom of the alkylene group may be substituted with an alkyl group having 1 to 5 carbon atoms or a halogen atom. M is bonded to the nitrogen atom of Y, and one of M and L forms an N ⁺ moiety by the bond with the nitrogen atom of Y.
   Z represents COO ⁻ , SO ₃ ⁻ , or PO ₄ ^— .
3. The hydrophilic coating film according to claim 1 or 2, wherein Y is selected from the group consisting of pyridine, piperidine, imidazole, oxazole, thiazole, pyrazole, imidazoline, pyrazine, benzimidazole, quinoline, isoquinoline, purine, and quinoxaline. Forming composition.
4. The composition for forming a hydrophilic coat film according to any one of claims 1 to 3, wherein Y is selected from the group consisting of pyridine, imidazole, imidazoline, and benzimidazole.
5. The composition for forming a hydrophilic coat film according to any one of claims 1 to 4, wherein the siloxane monomer is at least one selected from the following compounds.
   

   

   
6. The composition for forming a hydrophilic coat film according to any one of claims 1 to 4, wherein the siloxane monomer is at least one selected from the following compounds.
   

   
7. The composition for forming a hydrophilic coat film according to any one of claims 1 to 6, comprising 0.005 to 12% by mass of the siloxane monomer having a betaine group in terms of SiO ₂ solid content.
8. The composition for forming a hydrophilic coat film according to any one of claims 1 to 7, further comprising a metal alkoxide, a metal alkoxy digomer, or a metal alkoxide polymer.
9. The composition for forming a hydrophilic coat film according to any one of claims 1 to 8, further comprising inorganic fine particles, a leveling agent, or a surfactant.
10. A hydrophilic coating film obtained by coating the composition for forming a hydrophilic coating film according to any one of claims 1 to 9 on a substrate to form a coating film, drying the coating film, and baking the coating film. Method for forming a coat.
11. The method for forming a hydrophilic coat according to claim 10, wherein the coating film is dried at room temperature to 150 ° C and baked at 80 to 300 ° C.
12. The method for forming a hydrophilic coat according to claim 10 or 11, wherein the thickness of the film after baking is 3 to 150 nm.
13. A hydrophilic coat film obtained from the composition for forming a hydrophilic coat film according to any one of claims 1 to 9.
14. The hydrophilic coating film according to claim 13, which is a water droplet adhesion preventing film or an antifogging film.